1. Field of the Invention
The invention relates to detergents which contain as their builder or co-builder component an oligosaccharide which has been modified at its reducing end in such a way, instead of a hydroxymethylene aldehyde unit, a carboxyl unit is present at that end.
2. Discussion of Related Art
In addition to surfactants essential to their cleaning performance, detergents normally contain so-called builders of which the function is to support the work of the surfactants by eliminating hardness salts, i.e. essentially calcium and magnesium ions, from the wash liquor so that they do not negatively interact with the surfactants. One well-known example of builders which improve single wash cycle performance is zeolite Na-A which is known to be capable of forming such stable complexes, particularly with calcium ions, that their reaction with anions responsible for water hardness, particularly carbonate, to form insoluble compounds is suppressed. Another function of builders, particularly in laundry detergents, is to prevent redeposition of the soil detached from the fibers or generally from the surface to be cleaned and also insoluble compounds formed by the reaction of hardness-forming cations with hardness-forming anions onto the cleaned textile or rather onto the surface. So-called co-builders, generally polymeric polycarboxylates, are normally used for this purpose. In addition to the contribution they make towards multiple wash cycle performance, co-builders advantageously have a complexing effect on the cations responsible for water hardness.
The present invention seeks to make a contribution towards the use of so-called biologically degradable builders, i.e. naturally occurring substances or minimally modified derivatives thereof which are assumed to have better degradabiltiy than synthetic polymers of unsaturated mono- and dicarboxylic acids.